The present invention relates to a mobile portable device, such as a mobile portable communication device and to a concept for determining the position of the same.
Currently, a plurality of position detection or localization systems are known in conventional technology. The most common systems according to numbers are based on satellite-aided methods, which, however, necessitate the receipt of satellite radio signals and are thus frequently not usable or only to a limited extent inside buildings. Position detection systems for the usage within buildings are frequently based on methods necessitating field strength measurements of radio signals, such as GSM, Wi-Fi, Bluetooth or the same. Possibly, the cellular structure of such an arrangement of radio nodes within a network is also used for coarse localization. However, such a procedure frequently necessitates investments that bear an unfavorable proportion with respect to their usage. Also, these systems are frequently relatively inaccurate and allow, for example, no differentiation whether a position has been taken in front or behind an obstacle (wall, door, barrier, boundary line, etc.).
Other indoor positioning systems operate with beacons (based, for example, on infrared, radio and/or magnetism), which are located at previously known locations and thus enable identification of individual locations or their surrounding area, in particular by the limited range of signals emitted by the same. However, positioning is only possible at these locations and their surrounding areas defined by the limited range. A further type of local positioning works with sensors sensing the movement of a body, i.e. a person or an object, and can thus calculate its position in relation to a reference location. However, after a relatively short mission period, these systems become increasingly inaccurate, because over time and/or with increasing numbers of sensed movements, drift phenomenons have an effect, such that the inaccuracy of calculation becomes too great for practical usage.